1. Technical Field
This device and process relates to separation systems developed to recycle steel abrasive blast material by removing contaminates such as dust, paint, rust, etc. created during the pressure blasting process in which it is used.
2. Description of Prior Art
Prior art devices and processes of this type have relied on a variety of fixed and mobile separation apparatus that require the spent contaminated abrasive material either to be transported to a separate site and processed or processed on site on a continuing in use basis such as would be found in close circulation system, see for example U.S. Pat Nos. 4,943,368, 4,773,189, 4,449,331, 3,716,941, 2,810,991 and 3,934,374.
In U.S. Pat. No. 4,773,189 a separation system is disclosed for polymer blasting media which is cited to show multiple tasks separation system in which a contaminated blast products are collected, processed and reused in a continuous manner. The hazardous contaminates being directed to separate disposable storage units within the process.
Prior art U.S. Pat. No. 3,716,946 uses a recirculation close system with air separation as the initial separation with a secondary magnetic separator for removable of ferrous shot from the remaining non-ferrous contaminates.
U.S. Pat. No. 4,449,331 shows shot blasting machinery used in communication with a blast cabinet module. The device is characterized by a feed and lift conveyor recirculating system in communication with the blast cabinet for transportation of spent contaminated shot to the top of a vertical separation stack.
In U.S. Pat. No. 4,943,368 a non-metallic abrasive blasting material recovering process is disclosed having multiple steps of size classification, ferro-magnetic separation, gravity separation, electrostatic separation which is used in separation of non-conductive paint from conductive blasting media.
In U.S. Pat. No. 3,934,374 a sand blast reclamation system is disclosed using an airwash separator feeding a blast wheel. Contaminated air is directed to a fabric dust collector for filtration. A sand separator is positioned above the magnetic separator supplying usable sand back to the blast wheel via an internal elevator belt.
Finally, in U.S. Pat. No. 2,810,991 an abrasive blasting apparatus is disclosed that provides for a movable self-contained blasting and separation unit that recovers the spent contaminated shot as it is used and recirculates same through a separation process. The separator uses an air driven grit reclaimer in combination with a transfer chamber.
Prior art also shows mobile self-contained blasting units such as the Alpha 2000 Series manufactured by IPEC which is an attempt to provide a self-contained mobile separator in which interconnected steps are utilized to classify and clean shot from the contaminated material.